In electromagnetic braking apparatuses of conventional elevator hoisting machines, a plurality of insertion apertures are disposed on a surface of a fixed core that faces an armature. A rubber buffering member that reduces operating noise of the armature is inserted into each of the insertion apertures. The buffering members protrude from the insertion apertures (see Patent Literature 1, for example).
In electromagnetic braking apparatuses such as that described above, one problem has been that operating noise of the armature increases when the buffering members deteriorate. Deterioration worsens at high temperatures, for example, making the rubber buffering members smaller and harder. As a result thereof, reaction forces from the buffering members become lower than at first, giving rise to situations such as operating noise being increased, etc.
In answer to that, methods in which quality of operating noise is maintained by replacing the buffering members are also conceivable, but dismantling of the electromagnetic braking apparatuses may be difficult, depending on the construction or installed state of the electromagnetic braking apparatus, making it difficult to replace the buffering members.
On the other hand, compression-spring-type electromagnetic braking apparatuses have also been proposed that include mechanisms that push the buffering members directly in an axial direction using screws, etc. (see Patent Literature 2, for example).